title: Volumetric bone mineral density is an important tool when interpreting bone mineralization in healthy children.
abstract: In adults, it is well known that gender influences bone mass, but studies in children have shown contradictory results. Also, conflicting results have been reported regarding bone mineral density in obese children.
  
  
  OBJECTIVE
  To investigate bone parameters in healthy 8-year-old children and relate them to anthropometry and self-reported physical activity (PA).
  
  
  METHODS
  Bone measurements were performed with dual X-ray absorptiometry in 96 children, and questionnaires were used to assess self-reported PA.
  
  
  RESULTS
  Bone mineral content and density differed by gender. Eighteen percent of the children were overweight/obese and they had higher bone mineral content and density than children with normal weight. Bone mineral apparent density (g/cm(3)) of the lumbar spine did not differ, since the vertebral size differed, as was also the case between genders. Self-reported weight-bearing PA influenced bone mass in the hip.
  
  
  CONCLUSIONS
  PA influenced bone mineralization at this age. The differences in bone mineral content and density in healthy children would mainly be explained by the differences in bone size, reflected in body height and the width of the vertebrae. This indicates the importance of determining volumetric bone mineralization in children.
authors.affiliation: Department of Pediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden. susanne-e-sson@bredband.net
authors.forename: Susanne
authors.initials: S
authors.lastname: Eriksson
authors.forename: Dan
authors.initials: D
authors.lastname: Mellström
authors.forename: Birgitta
authors.initials: B
authors.lastname: Strandvik
mesh_terms: D001827:Body Height; D001835:Body Weight; D015519:Bone Density; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D012016:Reference Values